The present invention relates in general to tools for removing material from workpieces. More specifically, the invention relates to a cutting tool for a bar peeling operation.
Bar peeling is an operation in which a cutting apparatus is used to remove stock from a bar formed of ferrous material or nonferrous material. The stock may be, for example, millscale or cracked material produced during hot rolling of the bar. A typical cutting apparatus has several cutting heads which comprise holders containing cutting inserts.
The cutting edges of the inserts remove the material from the bar in the form of metal coils. Because the coils can interfere with the cutting operation, the inserts are usually formed with a groove or other chipbreaking geometry to break the coils into chips. However, the chips can also interfere with the cutting operation if they are not continuously removed from the vicinity of the cutting apparatus. A typical cutting apparatus produces relatively large chips which are difficult to remove.
One of the most commonly used inserts for bar peeling is a so-called xe2x80x9ctrigonxe2x80x9d insert, as shown and described in U.S. Pat. No. 4,035,888. The trigon insert produces relatively large chips. The insert also requires a relatively large amount of force for bar peeling.
U.S. Pat. Nos. 5,246,315 and 5,256,008 to Hansson et al. describe a cutting tool for a bar peeling operation in which the cutting heads each include a roughing insert and a finishing insert. The finishing insert extends a greater distance from the holder than the roughing insert. The patents do not address the problem of large chips being produced during the bar peeling operation.
In view of the above, it would be desirable to provide a tool for removing material from a workpiece, such as a cutting tool for a bar peeling operation, which is effective to reduce the size of the chips produced during the operation.
The invention relates to a tool for removing material from a workpiece. The tool includes a tool body equipped with at least one roughing head and at least one finishing head. In one embodiment, the finishing head includes a holder containing at least first and second finishing inserts. The first finishing insert has a cutting edge which extends a distance F1 from the tool body. The second finishing insert has a cutting edge which extends a distance F2 from the tool body. The distance F1 is less than the distance F2.
In another embodiment, the roughing head includes a holder containing at least first and second roughing inserts. The first roughing insert has a cutting edge which extends a distance R1 from the tool body. The second roughing insert has a cutting edge which extends a distance R2 from the tool body. The distance R1 is less than the distance R2.
In a preferred embodiment, the invention relates to a cutting tool adapted for a bar peeling operation. The cutting tool includes a tool body equipped with at least two roughing heads and at least two finishing heads. The roughing heads each include a holder containing at least first and second roughing inserts. The first roughing insert has a cutting edge which extends a distance R1 from the tool body. The second roughing insert has a cutting edge which extends a distance R2 from the tool body. The distance R1 is less than the distance R2 by the amount required to produce small chips or coils. The finishing heads each include a holder containing at least first and second finishing inserts. The first finishing insert has a cutting edge which extends a distance F1 from the tool body. The second finishing insert has a cutting edge which extends a distance F2 from the tool body. The distance F1 is less than the distance F2 by the amount required to produce small chips or coils.
The cutting tool of the invention produces smaller and more compact chips during the bar peeling operation, compared to a typical cutting apparatus, which makes chip removal much easier. The cutting tool produces bars having an excellent surface finish. The cutting tool can also be operated at reduced horsepower and reduced cost.